Advances in semiconductor processing and logic design have permitted an increase in the amount of logic that may be present on integrated circuit devices. As a result, computer system configurations have evolved from a single or multiple integrated circuits in a system to multiple hardware threads, multiple cores, multiple devices, and/or complete systems on individual integrated circuits. Additionally, as the density of integrated circuits has grown, the power requirements for computing systems (from embedded systems to servers) have also escalated. Furthermore, software inefficiencies, and its requirements of hardware, have also caused an increase in computing device energy consumption. In fact, some studies indicate that computing devices consume a sizeable percentage of the entire electricity supply for a country, such as the United States of America. As a result, there is a vital need for energy efficiency and conservation associated with integrated circuits. These needs will increase as servers, desktop computers, notebooks, Ultrabooks™, tablets, mobile phones, processors, embedded systems, etc. become even more prevalent (from inclusion in the typical computer, automobiles, and televisions to biotechnology).
In processors, workload changes can occur very quickly. This can cause dynamic switching capacitance (Cdyn) to change very quickly from very low to very high (e.g., due to a power virus condition). Many aspects of the design, such as a thermal design power (TDP) specification is set close to or at the highest end of the power consumption to satisfy rare but possible excursions into the highest extremes of the power range. High TDP specification increases overall system cost and also influences other characteristic such as overall product thickness.
Power delivery network specifications, due to the requirement of even shorter time response as compared to thermal issues, typically have an even higher maximum current requirement scenario, even when that scenario is too short to cause a significant increase in processor temperature. This type of requirement increases overall device size, type of components included in a system and overall cost.